Submitted to: Laboratory Publication
Publication Type: Other
Publication Acceptance Date: 3/18/2009
Publication Date: 3/18/2009
Citation: Riedell, W.E., Pikul Jr, J.L., Jaradat, A.A., Schumacher, T.E. 2009. Nitrogen Fertilizer and Long-Term Crop Rotation Effects on Soil Fertility, Corn Yield, and Seed Compostion. In: S. Coombes (ed.) 2008 Annual Report, Eastern South Dakota Soil and Water Research Farm, Brookings SD. Interpretive Summary: When grown in rotation, maize grain yield was 10 to 17% greater than monoculture. Significant increases in yield for maize grown in rotation were also recorded in experiments where N, P, and K soil test levels were high and pest populations were managed. Thus the rotation effect can have substantial positive influence on maize yields. Root function was improved and plant uptake of N, P, K, and Ca was increased in maize grown in rotation with soybean when compared with monoculture maize. We were interested to see if these same effects would take place under more complex rotations that included wheat and alfalfa. Understanding the complex interactions of soils, plants, and management practices is a first step towards development of agricultural systems that conserve soil and water resources while sustaining crop production. Thus, we were also interested in identifying soil, plant, and grain mineral nutrient variables that best discriminate N input treatments as well as rotation treatments from one another. The objectives of this study were to determine how soil mineral nutrients as well as maize growth, shoot and grain mineral nutrients, and yield would respond to monoculture, 2-yr C-S rotation, or 4-yr C-S-W/A-A rotation under different N input levels using univariate and multivariate statistical techniques.
Technical Abstract: Knowledge of complex relationships between soils, crops, and management practices is necessary to develop sustainable agricultural production systems. Objectives were to determine how maize (Zea mays L.) would respond to monoculture (C-C), 2-yr rotation (C-S) with soybean (Glycine max Merr.), or 4-yr rotation (C-S-W/A-A) with soybean, wheat (Triticum aestivum L.), and alfalfa (Medicago sativa L.) under different N input levels. We evaluated N fertilizer input (8.5 or 5.3 Mg/ha yield goal, or no N) and crop rotation (C-C, C-S, or C-S-W/A-A) treatment effects on soil minerals (N, P, K, S, Ca, Mg, Fe, Mn, and Zn) and their subsequent effect on shoot dry weight and mineral concentrations, grain yield, and grain composition (oil, starch, and mineral concentrations) using univariate and multivariate statistical tests. Soil under C-S-W/A-A rotation had greater NO3-N and less extractable P than other rotations. Significant input x rotation interactions revealed that shoot concentrations of N, Ca, and Mg were less while P, K, and Zn were greater at no N input for the C-C rotation compared with other N input/rotation treatments. Increased soil NO3-N, increased plant Ca concentration, and increased grain N and grain S concentrations were most important in differentiating C-S-W/A-A rotation from C-C and C-S rotation treatments. No N input resulted in less yield and kernel N concentration within the C-C and C-S rotations but not C-S-W/A-A. Thus, growing maize in extended rotations that include forage legumes may be a more sustainable practice than growing maize in either monoculture or 2-yr rotation with soybean.